The Department of Physiology and Biophysics, Stony Brook University School of Medicine, Stony Brook, NY, 11794, USA.
Sci Rep. 2020 May 26;10(1):8744. doi: 10.1038/s41598-020-65761-z.
Gap junction channels made of different connexins have distinct permeability to second messengers, which could affect many cell processes, including lens epithelial cell division. Here, we have compared the permeability of IP and Ca through channels made from two connexins, Cx43 and Cx50, that are highly expressed in vertebrate lens epithelial cells. Solute transfer was measured while simultaneously monitoring junctional conductance via dual whole-cell/perforated patch clamp. HeLa cells expressing Cx43 or Cx50 were loaded with Fluo-8, and IP or Ca were delivered via patch pipette to one cell of a pair, or to a monolayer while fluorescence intensity changes were recorded. Cx43 channels were permeable to IP and Ca. Conversely, Cx50 channels were impermeable to IP, while exhibiting high permeation of Ca. Reduced Cx50 permeability to IP could play a role in regulating cell division and homeostasis in the lens.
间隙连接通道由不同的连接蛋白组成，对第二信使具有不同的通透性，这可能影响许多细胞过程，包括晶状体上皮细胞的分裂。在这里，我们比较了由两种在脊椎动物晶状体上皮细胞中高表达的连接蛋白 Cx43 和 Cx50 组成的通道对 IP 和 Ca 的通透性。通过双全细胞膜片钳/穿孔膜片钳同时监测连接电导来测量溶质转移。用 Fluo-8 负载表达 Cx43 或 Cx50 的 HeLa 细胞，通过贴片电极将 IP 或 Ca 递送至一对细胞中的一个细胞，或递送至单层细胞，同时记录荧光强度变化。Cx43 通道对 IP 和 Ca 是可渗透的。相反，Cx50 通道对 IP 是不可渗透的，而对 Ca 的通透性较高。Cx50 对 IP 的通透性降低可能在调节晶状体中的细胞分裂和动态平衡中发挥作用。
